Demo category is promoted

[e-grigorov]

Currently, "New" wizards (Entity, Enum, Functionblock, Model etc.) don't have an option to enter the category. On "Finish", the category is automatically filled with "demo". This behaviour is somehow hidden and I can see two options to fix it:

• add category to the wizards
• don't fill automatically the category - that's my preferred option because the category is optional